the this circuit helps us to repeat the behaviors that make us happy while avoiding those that make us miserable. but as any adult knows, pleasure is not always good for you. tonight we'll also explore particularly dangerous forms of pleasure-seeking, addiction. long considered to be a moral weakness, addiction is now understood to be a biological disease. finally, we will explore the role that emotions play in decision-making and social interaction. next month, in part two of the emotional brain, we will turn our focus to negative emotions such as fear and anxiety. joining us tonight, a group of scientists who have devoted their lives to understanding the emotional brain. daniel salzman, he studies how the brain assigns an emotional value to the information that it receives from the five senses. he is an assistant professor of sky tri and neuroscience at columbia university. wolfram schultz. he studies how the brain's reward systems affect decision-making and learning. he is a professor of neuroscience at cambridge university and a fellow of the royal society. nora volkow. her researc